This invention relates to an apparatus and method of providing means for an archer to automatically choose the angle of flight of an arrow, this angle being continuously displayed to the archer, and adjusted to comply with the exact distance from the target, normally a deer, and, normally from a tree stand. The exact angle is calculated from a pendulum type sight, and is displayed to the archer by a pin sight, this pin sight being a part of this archery bowsight invention.
It has been customary for an archer hunter to find a certain area to hunt, and to build a tree stand in the area, climb to the tree stand, and wait for a deer to appear. These tree stands are very efficient, as it is seldom that a deer pays any attention to anything in the trees, as these are not a threat to the deer, animals on the ground being the natural enemy of the deer.
Now, shooting a bow from a tree stand is a very exacting shot for the archer. The normal shot being on a more or less level area, and the distance of travel of the arrow being more easily ascertained, than from a tree stand. These shots from a tree stand vary from a vertically downward shot to a distance of 70 yards. Therefore, the angle of the flight of the arrow conforms to the curvature of a mathematical equation for distance, time, velocity, and gravity, from angles of zero degrees to angles of some 110 degrees, and distances of from zero yards to some 70 yards. The normal archer is unable to attain any accuracy for shots of over 70 yards.
Several approaches have been provided for aiding the archer in sighting the arrow for these different distances. Holt, in U.S. Pat. No. 4,715,126 teaches a bow sight to be attached onto the mounting framework of a bow, and having several moveable pin sights within the archers sight, as he lines up the arrow on the target. These moveable pin sights have been placed within the archers sight in a pre sight bore trial, and, as a target is chosen, the archer determines mentally what the distance is, and chooses the pin sight which matches the distance to the target. These types of pin sights are very effective for known distances to the target, however, in a moment of excitement, determining the exact distance to the target becomes rather choicy, quickly, and is prone to human error.
Another approach is taught in the art of Johnson, in U.S. Pat. No. 4,846,141, whereby a framework is affixed to the bow, and again a series of pin sights are adjustably fitted within the sighting area of the archer, pre located to fit the bow, the archer, and the various distances to the target, and, the archer mentally determines the distance to the target, to the best of their ability, chooses the correct sighting pin, and releases the arrow. Here again, human error determines the exactness of the shot.
Still another approach is taught in the art of Lowry, in U.S. Pat. No. 4,974,328, whereby a Pendulum is used to correct for the actual distance to the target, allowing the archer to adjust a fixed pin sight attached to the pendulum, and, after bore sighting the bow, with the archers strength, the pin sight is fixed in that position relative to the pendulum. The problem with this fixed pin sight is that for different bows, the arrow trajectory will be different, and, these fixed pin sights will not readily adapt to these changes in arrow trajectory, again reverting the archer to a guess type of shot.